not wearing a helmet is just stupid. It's not just the heavy accident; it's the case of a light accident, that damages the helmet, and you walk away with a headache. Some years ago, a friend of a friend in vienna had an accident with his bicycle, was under intensive care for 2 days or so, then died. no helmet.
at a harley meeting in Austria it was once allowed not to wear a helmet. so we had a ride at the lakeside, without helmet, was great. but just too dangerous.
myself, I broke my hip (!!) when I had a quite simple accident with my bicycle, had two 5hrs-operations to get it fixed. A lot can happen within a second.
It's better to look not that cool and wear a helmet, then not wearing a helmet and then -bang- you're not even able to wipe your a@@ by your self, cos you'r brain is totally damaged. your rc car got sold, to pay for food... what a great life...

but at least, you looked cool